PS4 is state of the art it is not a medium spec PC.

Hello I haven't posted here for a long long time. In fact I was most posted most during pre and post launch of PS3 although I love the PS3 for what it is a games machine the actual hardware specs really intrested me and I spent hours reading everything I could on the Cell and anything else I could get my hand on even reading links to detailed spec sheats and discussions on the IBM forums in the engineers section. I then discussed my thoughts and impressions and made predictions on what the Cell could mean for games with the PS3 (it would be very intresting to read those posts again some time to see how much I got right/wrong).

The time is with us again and I have taken a keen intrest in what Sony is doing with the PS4 it is much harder to gauge this as there are not much in techincal documentation or cpu benches like there was with the Cell to base any of my theories or predicitons on. Therefore allot of my theories this time is more supposition and not supported by hard facts but based on what I have managed to read on the varius aspects of both the hardware and software from AMD, Cerny (Sony), Some of the more reputible Beyond 3D information on things like huma and tidbits from devs on forums and twitter.

Why am I posting this after all this time. Well I have just read lots of forums including Neogaf and its getting to me that people are writing off the PS4 as only as powerfull as a medium range PC (or even less powerfull in some cases) and the often addage that the hardware because it is based on 86x 64 base processor and Southern Island GPU's are out of date and old tech (even before the PS4 hits the shelves).

Now if your PC centric and you look at the equivilant AMD GPU the Jaguar 8 core chipset look at the pure Gflop performance this conclusion seems on the surface to be a reasonable one. However this is a huge mistake this is not a CPU a GPU a Sound Processor and it is a APU. That means that every peace of hardware is linked together on the same die therefore while the individual componants can be compared to its PC equivilants the fact that every single componant is on the same die means that that there is in order of maginitude efficency between all of its parts.

When your building a PC you can fit any number of CPU's into your MB similalry any number of Memory sticks or many types of strengths of GPU's. The mother board is designed therefore to support many different configurations and similarly the software must also support all these types of configurations from drivers to OS to be able to make all these pieces working together to achieve the desired goal of playing a game.

Both Sony and MS had design goals decided what they could achieve taking into account their aims (e.g. media, kenect, games for MS, ganes, media, video streaming for Sony (these are just examples)) the amount of power they could use taking into consideration heat disepation and cost.

So once Sony new how much power and cost they could budget for they went about building (with AMD) the best peace of kit taking in mind the demands of both internal and external studio's. Based on the project constraints (power, cost, heat dispertion, developer demands, project goals) they then arrived with AMD with their solution.

They also took what they learnt what went wrong or write the PS3 and factored this with the PS4 to.

What they liked about the PS3 was the shear power and flexibilty of the Cell to do remarkable things (Beyond 2 Souls, TLOU, God of War etc) what they didn't like was that the developers outside of Sony found it so hard to use and program for. Also the split memory pools caused developers issues and together with the weaker GPU (compared to Xbox 360) this caused most multiplats to not be able to leverage the PS3's potential and meant that most multiplats were better on the Xbox 360.

Sorry for rambling but the insights that Cerny has given us into the design of the PS4 informs you of what they (Sony) are trying to achieve with the PS4 and that background does give you some insight into what the PS4 is all about.

Ok we have allready covered that the PS4 is a APU and that means all the componants or on one die. What does this mean exactly.

Well what it means is that the degree of seperation is much smaller. High bandwidth connect all these componants together and the bandwith/bus(es) is designed so that it takes advantage of the fact that all the componants are fixed and effiecent. The way that the PS4 can use its buses ONION, ONION+ and Garlic (to CPU to GPU via Cache (10 GB Sec) to CPU to GPU avoiding GPU cache (the same 10 GB sec) and CPU and GPU to GDDR5 (20 GB sec CPU 176 GPU) all read/write. )

In addition they have added volatile tag so that the CPU and GPU can work on asynchronous compute for the system memory.

What does this mean exactly?

WIth the PC the componants are further apart and the path between the GPU and CPU is small in addition in order for the CPU or GPU to comunicate they use cache. Also the CPU language and the GPU language is different meaning that there is a layer there that needs to be done in order on both a hardware and software level that needs to work before the CPU and GPU can work together in order to produce the desired result. Cache misses are the bane of the PC world its why people scoff at tflop or gflop numbers because most processors relie on cache and cache misses are very costly terms of the amount of time it takes to process the task. In order to get around this the CPU for example is OOE or out of order which means that it can work on things while it is waiting for the piece of information it needs is "found" on cache.

Without going into to much detail the steps between the CPU sending a job to the GPU and asking for the results back is in computer terms very time consuming because of bandwidth, cache misses / cache flushes, coverting instrustions in memory from what the cpu understands to what the GPU understands doing the job and going bak to the cpu repeating the process.

The way the PC mitigates this is by being OOE and also by "brute force" in that the CPU and GPU are so quick and powerfull that they process the information very quickly once they have the instruction or job to do. Thus any time wasted due to cache misses / cache flushes are mitigated the faster and more powerfull the CPU and GPU are the more they "hide" this. However this is why people scoff at theoretical performances. Due to infecancys in the way this works and the fact that a job rarely uses 100 percentof the silicon real estate of the CPU/GPU the theoretical maximum of the PC are very rarely reached.

It's obviously more complicated than that because you also have to take into account software layers in that the PC also has software layers. For example Windows OS has to cater for all possible componants and have the drivers to tell the componants what to do. Due to how high the software is working it is only telling the hardware how to proceed with a job/instruction in a general way and not telling it how to do it in the best way (most efficient).

It is speculated on the other hand that the PS4 has Huma across its APU. This means that not only is the componants close to each other it can work in conjunction with each other in an efficent manner. So you tell the PS4 to do a collision detection job for example and it goes to the CPU which does its bit (usuing the CPU to do the bit that its good at) it passes the rest of the job to the GPU straight or via a unified memory which is flagged for a job. The GPU understands what it needs to do without any translation and does its bit and either sends it to the memory or sends the result to the CPU straight using the onion/onion + bandwidth. It can even write the result to the memory flagging it for the CPU the CPU does extra work and writes the result flagging this bit in the memory and GPU can take this back again. This is what is meant by asynchonus compute it can work together on a problem in a way that current PC's just not able to do.

So what does this mean in real world performance.

This is cutting edge technology which is why I am a little annoyed when I see PC gamers call the PS4 set up old. It's not the fact is the PCI exrpres variations and the way that the CPU and GPU work are old techonolgy with only incremental bandwidth changes and its basics have been the same for a very long time. The amount of power that the CPU and GPU are using (per watts and per how much real estate they use) is covering up how terribly ineffcient the process is.

If the PS4 is huma and many of the talks that Mark Cerny has given together with how Huma works and the way in which the PS4 is set up seems to suggest that it is. Then due to the fact that the CPU and GPU can communicate and work on projects in a way in which has not been done before means that it in order of times more efficient that its PC equivilants how many times in order remains to be seen.

The other piece of how powerfull the PS4 is is the GPU itself this is not just a 1.8tflop GPU it is modified extensivly above and beyond what GPU's are today so stacking up a stock AMD 2tflop GPU and putting up against the PS4 GPU and saying the AMD is more powerfull is very far from the whole picture.

A normal AMD tahiti 7900 GPU has 2 ACE's and only 4 ques (not sure on this) however I believe the one on the Xbone has between 2 and 8 ques per ACE (Asynchronous Compute Engines) for a total of 4 or 16 ques to be worked on at any one time (Sorry I can only find four ques at the moment via google e.g. 2x2 but im sure I read a later spec sheet that said it had 8 to make it 16 so I cant be sure which is correct maybe someone here can confirm which is correct).

Sorry I am so vauge on the PC and Xbone specs on AC's soon as I find the relevant information I will update the OP.

Anyway the PS4 has 8 ACE's and has 64 ques. These are mostly used for the mangment of using the GPU for compute or GPGPU physics, collision detection, audio raytracing are examples of compute.

What does this mean?

Ok I have read that shadowmaps (from a dev) are terribly ineficient on GPU's as a job. Now I don't now exactly what this means in terms of how much real resources used on a GPU to do this job but lets say for the sake of argument that this job is 50 percent give or take on GPU's as a whole (to make things simple). Now a Nvidia Titan will still do this job really quickly even though its only using 50 percent of its recources to do this job due to brute power but effectivly the efficency of this task for this (made up) example means that its only able to do this job at an effective rating of 50 percent of its tflop rating (6tflop).

In the mean time the CPU wants to offload a compute task (collision detection on mutliple objects for example) and sends that to the titan. This is not straight forward due to the seperation as detailed earlier. Due to the fact that the designer doesnt know that a state of the art GPU is on the other end they may even decide that collision detection is best done on the CPU due to the bandwidth/communication/OS overhead/high API wrapper and the fact that a less powerfull GPU might be present.

(optimised for Nvidia or AMD may mean that the job is done on the that brands GPU due to the correct software drivers/hardware being present on the GPU).

Anyway the upshot is that both the CPU and GPU on the PC are more than capable of doing whatever compute jobs are there its just there are issues meaning that PC is inheritly inefficent for CPU to GPU communications. PCIe 3 is 16 Gig sec have all the other issues mentioned earlier.

The PS4 has 30 Gig sec transfer of information between it. Also due to direct commuinicaiton and Volatile tags cache misses and ineffcies are cut down.

In addition to this while the PS4 GPU is running the shadow map GPU taks at 50 percent of its capabilities it can use (theoretically) 50 percet of the rest of the GPU to many compute jobs with 8 ACE's and 64 queues ready to fill any slack in the GPU for use as compute.

Lets be clear the Cell had a gflop rating of about 216 if I remember correctly to use on compute and gpu tasks (but also had to do audio AI etc etc) this monster has shared resources of up to 1.8 Tflops for GPU and compute tasks. In the 50 perecent scenario that means that 900 gflops 4.5 times that of cell can be used for compute jobs.

And its even better than that its not just 1 job at 50 percent. It can do many jobs balancing across what the CPU is good at and what the GPU is good at at the same time the CPU and the GPU constantly reading writing and updating fine grained compute spread over multiple jobs.

In conclusion:

What does this mean

While on paper the componants may look middle of the road the actual design from a sofrware and hardware point means that the tech is state of the art do not confuse a lower tflop rating with old techonolgy. This is brand new technology in the following ways:

The most powerful APU in existance
A GPU with huge bandwidth resources to a very large amount of GDDR5
A GPU that in theory can use all its 1.8 tflop resources ot both GPU and GPGPU at the same time in a way that no other GPU on the market is capable of at the moment especally when you consider that the API is "close to the metal"
The CPU and GPU are not only part of a APU i.e. on the same die they look to support huma in that both CPU and GPU can freely share jobs on the fly giving code to the strengths of system and not having a bottleneck in either comunicaitons between each other nor issues with bandwidth between each other for a system whose processors are bound tightly together.

Speculation in what that means in games

Basicly just like Cell was able to do some pretty amazing things despite the fairly week GPU in first party hands. It produced beautifull games like TLOU, God of War, Uncharted for example. It also has beautiful games like GT6 and Beyond 2 souls coming soon.

When Mark Cerney is talking about easy to use (access as pure GPU) the GPU is easy to use due to unified memory without any concern for edram or hard to use custom hardware (Cell).

When he was talking about having something in the tank or explotiable resources down the line he was talking about the fine grained computing with huma and the modfied GPU.

Having a 1.8tflop GPU means that we should see and are seeing a noticeable increase in visual fedility as we have seen in Killzone Shadow fall at 1080p 30fps or 1080p at 60fps for mulitplayer.

What we might see in the future is less to do with common GPU things like tessalation, shadows and visual fedelty but distructable environments not seen before, effects that are just impossible on old consoles.

PS4 may even push the PC's in ways that have not been done due to its use of physical effects that have not been seen in games before because the reources of the GPGPU are aviable in a very real way and not part of just a one off effect that happens just in one game.

I believe we are allready seeing glimpses of this future. With collisions, physics and use of voxels in Resogun, the particle effects from Infamous Second Son, And volumetric effects from Deep Down.

I am very exited by the future of the PS4 and will be very intrested in the techical aspects of the games of the current generation.

(NOTE I will re-edit this post for mistakes etc but want to post it just in case I lose the text please bare with me)

PS4 may even push the PC's in ways that have not been done due to its use of physical effects that have not been seen in games before because the reources of the GPGPU are aviable in a very real way and not part of just a one off effect that happens just in one game.

PC has had GPU-accelerated physics for a very long time, and it has been seen in countless games. Saying putting that out there. The PS4 won't be doing anything beyond what PhysX has already delivered.

PC has had GPU-accelerated physics for a very long time, and it has been seen in countless games. Saying putting that out there. The PS4 won't be doing anything beyond what PhysX has already delivered.

,

I think the point is it will do it better than physX , i remeber when it was first introduced on the PC and it was a massive drain on the GPU. I even went to the extreme of putting a cheap second GPU in just to run physX. It is still a massive drain on the GPU and as he has mentioned they overcome it by throwing huge ammounts of raw power in from fast CPU's and insanely fast nd power hungry GPU's. The PS4 will do all this in a more efficient way , I think thats his point on saying the PC architecture may learn something.

Its a very interesting article and helped me understand the architecture alot more. Nice One!!

PLAYSTATION 4 is FAAAARRRRRRRRR MORE than "just graphics"

finally! FINALLY!
someone else out there understands just how ground breaking this technology is!
PLAYSTATION 4 will BLOW us away beginning next year

(now mind you, there are early games using compute-based gameplay {Knack, Res0gun, inFAMOUS: Second Son, Deep Down, etc.})

when people get their hands on the second generation games
im not talking about graphics (of course those will amaze all as well) im talking about world simulation and compute-based gameplay and physics

in order to have compute-based gameplay your cpu and gpu need to be as close as possible to each other and have the abilty to "speak" to each other so they can work on new customized algorithms and always stay up to date on what the other is doing (http://www.amd.com/us/products/techn...ges/hsa.aspx#3)

heres one glimpse of some Compute Based Gameplay made possible by the magic of hUMA

note how the real-time fluid dynamic fire interacts in real time with the wind calculations from the players tornado spell

(fire fluid dynamics swirl due to the wind calculations, also notice how the tornado deflects and splits the fire down the middle {developers can get all sorts of exciting and eye-catching residual and surplus effects because of the real-time nature})

can help cut down development time and costs too because the artists and programmers dont have to go in and hand make every little effect. once again due to being real time the effects "just happen"

now of course if a dev wants something to look just right theyll hand tweak it anyway but the off-shoot effects of interacting with physics in a true real time nature will be STUNNING and randomized EVERY time

THATS what i mean when i say compute-based gameplay (when a player character is directly interacting with real-time physics)

PC has had GPU-accelerated physics for a very long time, and it has been seen in countless games. Saying putting that out there. The PS4 won't be doing anything beyond what PhysX has already delivered.

I will reply with a quote from Mark Cerney regarding the large diffrances even on a hardware level (to say nothing of bloated OS and high level Direct X drivers covering multiple GPU's) on the diffrances between PC's and the PS4.

Cerny envisions "a dozen programs running simultaneously on that GPU" -- using it to "perform physics computations, to perform collision calculations, to do ray tracing for audio."

But that vision created a major challenge: "Once we have this vision of asynchronous compute in the middle of the console lifecycle, the question then becomes, 'How do we create hardware to support it?'"

One barrier to this in a traditional PC hardware environment, he said, is communication between the CPU, GPU, and RAM. The PS4 architecture is designed to address that problem.

"A typical PC GPU has two buses," said Cerny. "There’s a bus the GPU uses to access VRAM, and there is a second bus that goes over the PCI Express that the GPU uses to access system memory. But whichever bus is used, the internal caches of the GPU become a significant barrier to CPU/GPU communication -- any time the GPU wants to read information the CPU wrote, or the GPU wants to write information so that the CPU can see it, time-consuming flushes of the GPU internal caches are required."

The three "major modifications" Sony did to the architecture to support this vision are as follows, in Cerny's words:

"First, we added another bus to the GPU that allows it to read directly from system memory or write directly to system memory, bypassing its own L1 and L2 caches. As a result, if the data that's being passed back and forth between CPU and GPU is small, you don't have issues with synchronization between them anymore. And by small, I just mean small in next-gen terms. We can pass almost 20 gigabytes a second down that bus. That's not very small in today’s terms -- it’s larger than the PCIe on most PCs!
"Next, to support the case where you want to use the GPU L2 cache simultaneously for both graphics processing and asynchronous compute, we have added a bit in the tags of the cache lines, we call it the 'volatile' bit. You can then selectively mark all accesses by compute as 'volatile,' and when it's time for compute to read from system memory, it can invalidate, selectively, the lines it uses in the L2. When it comes time to write back the results, it can write back selectively the lines that it uses. This innovation allows compute to use the GPU L2 cache and perform the required operations without significantly impacting the graphics operations going on at the same time -- in other words, it radically reduces the overhead of running compute and graphics together on the GPU."
Thirdly, said Cerny, "The original AMD GCN architecture allowed for one source of graphics commands, and two sources of compute commands. For PS4, we’ve worked with AMD to increase the limit to 64 sources of compute commands -- the idea is if you have some asynchronous compute you want to perform, you put commands in one of these 64 queues, and then there are multiple levels of arbitration in the hardware to determine what runs, how it runs, and when it runs, alongside the graphics that's in the system."
"The reason so many sources of compute work are needed is that it isn’t just game systems that will be using compute -- middleware will have a need for compute as well. And the middleware requests for work on the GPU will need to be properly blended with game requests, and then finally properly prioritized relative to the graphics on a moment-by-moment basis."

This concept grew out of the software Sony created, called SPURS, to help programmers juggle tasks on the CELL's SPUs -- but on the PS4, it's being accomplished in hardware.

The team, to put it mildly, had to think ahead. "The time frame when we were designing these features was 2009, 2010. And the timeframe in which people will use these features fully is 2015? 2017?" said Cerny.

"Our overall approach was to put in a very large number of controls about how to mix compute and graphics, and let the development community figure out which ones they want to use when they get around to the point where they're doing a lot of asynchronous compute."

Cerny expects developers to run middleware -- such as physics, for example -- on the GPU. Using the system he describes above, you can run at peak efficiency, he said.

"If you look at the portion of the GPU available to compute throughout the frame, it varies dramatically from instant to instant. For example, something like opaque shadow map rendering doesn't even use a pixel shader, it’s entirely done by vertex shaders and the rasterization hardware -- so graphics aren't using most of the 1.8 teraflops of ALU available in the CUs. Times like that during the game frame are an opportunity to say, 'Okay, all that compute you wanted to do, turn it up to 11 now.'"

Sounds great -- but how do you handle doing that? "There are some very simple controls where on the graphics side, from the graphics command buffer, you can crank up or down the compute," Cerny said. "The question becomes, looking at each phase of rendering and the load it places on the various GPU units, what amount and style of compute can be run efficiently during that phase?"

i tried to simplify this in my OP but as you can see there is a vast differance in the way the hardware is able to be used on the PS4 which is just not possible on the PC. With limited queues and ACE's and the way the PCIe and cache and the lack of understanding between CPU and GPU meaning that expensive cache flushis are necessary PS4 is a huge step above in CPU and GPU communication in terms of both bandwidth, efficency and the amount of compute jobs it can do on the GPU at the same time as it is doing GPU tasks.

If the GPU is doing GPU tasks with various efficency's of its silicon i.e. gemotery, shadow maps, tessilation, shaders etc. The bits of the GPU that are not being used during each of these tasks can be used for GPGPU compute tasks in order that the GPU is hitting its close to its full 1.86 tflop rating.

I would imagine that this would make the GPU in order of times more efficent at GPGPU than its PC equivilants. And that the only way that a PC could manage this would be to use the Brute force of its GPU's to compensate for their inefficencys. BTW AMD's new wrapper API seems to suggest that they have develope sofware that is closer to the metal so this is another way that PC's can gain some ground on the advantages that consoles generally have with their fixed hardware.

Wow, blast from the past. Welcome back Terarrim

Thanks Mynd and others for the welcome ( I remember you to Mynd).

Good example carlWINSLOW deep down is a good glimpse of real time volumetric fire and volumetric wind that interact to create a fire tornado.

This is the type of dynamic effects that will have a huge effect on both visuals and have a real new way to effect gameplay in the future for the PS4.

I will reply with a quote from Mark Cerney regarding the large diffrances even on a hardware level (to say nothing of bloated OS and high level Direct X drivers covering multiple GPU's) on the diffrances between PC's and the PS4.

i tried to simplify this in my OP but as you can see there is a vast differance in the way the hardware is able to be used on the PS4 which is just not possible on the PC. With limited queues and ACE's and the way the PCIe and cache and the lack of understanding between CPU and GPU meaning that expensive cache flushis are necessary PS4 is a huge step above in CPU and GPU communication in terms of both bandwidth, efficency and the amount of compute jobs it can do on the GPU at the same time as it is doing GPU tasks.

If the GPU is doing GPU tasks with various efficency's of its silicon i.e. gemotery, shadow maps, tessilation, shaders etc. The bits of the GPU that are not being used during each of these tasks can be used for GPGPU compute tasks in order that the GPU is hitting its close to its full 1.86 tflop rating.

I would imagine that this would make the GPU in order of times more efficent at GPGPU than its PC equivilants. And that the only way that a PC could manage this would be to use the Brute force of its GPU's to compensate for their inefficencys. BTW AMD's new wrapper API seems to suggest that they have develope sofware that is closer to the metal so this is another way that PC's can gain some ground on the advantages that consoles generally have with their fixed hardware.

Thanks Mynd and others for the welcome ( I remember you to Mynd).

Good example carlWINSLOW deep down is a good glimpse of real time volumetric fire and volumetric wind that interact to create a fire tornado.

This is the type of dynamic effects that will have a huge effect on both visuals and have a real new way to effect gameplay in the future for the PS4.

But PC can actually do all that too. Raytracing audio, collision detection, physics. They are already doable on PC. And PC has also had GPGPUs for desktop gaming PCs for a long time too. And loading physics and raytracing onto the GPU just means less power for actual graphics rendering. The PS4 GPU is only about as powerful as an AMD HD6870. It raises the bar from prior consoles, and thus sets the new lowest common denominator, but no physics on the PS4 hasn't already been outdone in numerous PC games.

It was a nice, long read, but the PS4 just isn't anything but a mid-spec PC.

finally! FINALLY!
someone else out there understands just how ground breaking this technology is!
PLAYSTATION 4 will BLOW us away beginning next year

(now mind you, there are early games using compute-based gameplay {Knack, Res0gun, inFAMOUS: Second Son, Deep Down, etc.})

when people get their hands on the second generation games
im not talking about graphics (of course those will amaze all as well) im talking about world simulation and compute-based gameplay and physics

in order to have compute-based gameplay your cpu and gpu need to be as close as possible to each other and have the abilty to "speak" to each other so they can work on new customized algorithms and always stay up to date on what the other is doing (http://www.amd.com/us/products/techn...ges/hsa.aspx#3)

heres one glimpse of some Compute Based Gameplay made possible by the magic of hUMA

note how the real-time fluid dynamic fire interacts in real time with the wind calculations from the players tornado spell

(fire fluid dynamics swirl due to the wind calculations, also notice how the tornado deflects and splits the fire down the middle {developers can get all sorts of exciting and eye-catching residual and surplus effects because of the real-time nature})

can help cut down development time and costs too because the artists and programmers dont have to go in and hand make every little effect. once again due to being real time the effects "just happen"

now of course if a dev wants something to look just right theyll hand tweak it anyway but the off-shoot effects of interacting with physics in a true real time nature will be STUNNING and randomized EVERY time

THATS what i mean when i say compute-based gameplay (when a player character is directly interacting with real-time physics)

its not just "window dressing"

Originally Posted by archie123

,

I think the point is it will do it better than physX , i remeber when it was first introduced on the PC and it was a massive drain on the GPU. I even went to the extreme of putting a cheap second GPU in just to run physX. It is still a massive drain on the GPU and as he has mentioned they overcome it by throwing huge ammounts of raw power in from fast CPU's and insanely fast nd power hungry GPU's. The PS4 will do all this in a more efficient way , I think thats his point on saying the PC architecture may learn something.

Its a very interesting article and helped me understand the architecture alot more. Nice One!!

Originally Posted by mynd

Wow, blast from the past. Welcome back Terarrim.

Originally Posted by Foraeli

But PC can actually do all that too. Raytracing audio, collision detection, physics. They are already doable on PC. And PC has also had GPGPUs for desktop gaming PCs for a long time too. And loading physics and raytracing onto the GPU just means less power for actual graphics rendering. The PS4 GPU is only about as powerful as an AMD HD6870. It raises the bar from prior consoles, and thus sets the new lowest common denominator, but no physics on the PS4 hasn't already been outdone in numerous PC games.

It was a nice, long read, but the PS4 just isn't anything but a mid-spec PC.

But PC can actually do all that too. Raytracing audio, collision detection, physics. They are already doable on PC. And PC has also had GPGPUs for desktop gaming PCs for a long time too

I never said the PC cant do it it can do those things. It can but its very ineficent at doing it. And it is limited to how may operations it can to at the same time. Likewise PC devs don't have the resources to target individual cards and their strengths.

You seem to have read it and dismissed it despite me cleary showing that the PS4 has greater bandwidth than PC between CPU and GPU and has in order of times efficency due to how the architecture is both closed box, greather bandwidth, and taking into account cache misses and cache flushes which introduce stalls/bottlnecks in the current PC architecture.

And loading physics and raytracing onto the GPU just means less power for actual graphics rendering.

This is not quite true. I have allready given examples where when the GPU is doing a task it has huge amounts of the silicon that it is not using it is not operating at 100 percent effciency.

For example:

"Usually when I talk about this," said Cerny, "people say, 'but wait, won't that make the graphics worse?'

"Well, if you look at a frame and everything that's being done in that frame, a lot of phases within that frame – it's like 1/30 of a second – some of these phases don't really use all of the various modules within the GPU.

"Shadow map generation tends not to use ALU [Arithmetic Logic Units] very much, so it's a really optimal time to be doing all of those other tasks."

So on any GPU in PC you have lots of headroom that is going to waste at this point. The PS4 GPU is able to use these ALU's that are spare to do GPGPU work not only one or two tasks like modern PC processors but up to 64 tasks can be qued up for when these resources are available that is a huge differance in tech and design aproach.

The PS4 GPU is only about as powerful as an AMD HD6870.

im sorry but this is an old GPU its not GCN its PCIe 2 not 3 and direct X 11 and is not GCN enabled. the PS4 GPU is direct X 11.2 and smokes the PCIe 2 for bandwidth.

A better example looking at AM GPU's is 7850 which has the following specs:

So overall the PS4 compares favourably in many aspects and has better bandwidth, more tech advanced (direct x 11.2), and smokes it on GPGPU capabilites. In addition it has nearly twice the bandwidth to the CPU as the 7850 with the abilty for cache bypass or to leave volatile marking on memory so that the CPU can work on the memory without doing a cache flush.

While there are much faster GPU's out there the architecture of the PS4 GPU is state of the art and no other card has the bandwidth or efficency due to both sofware and hardware for the potential for compute.

It raises the bar from prior consoles, and thus sets the new lowest common denominator, but no physics on the PS4 hasn't already been outdone in numerous PC games.

Well we haven't seen what the PS4 is capable of it will take a while but the demonstrations of particles in Second Son, the use of volumetrics on different elements of deepdown and even the sheer amount of voxoles and collision detection on Rasogen are up there with the best examples of GPGPU compute and the PS4 hasnt even launched.

It was a nice, long read, but the PS4 just isn't anything but a mid-spec PC

I disagree for the following reasons

1. PS4 is the most powerfull APU bar none no PC has this technology at this level
2. mid or high range PC's are not capable of Huma
3. No GPU and CPU on any PC have access to 8 GB of GGR5
4. No CPU has a faster bandwidth between CPU and GPU neither do they have as the abiltiy to bypass cache neither do they use volatile markers so that CPU and GPU can work on the same code in memory.
5. No mid range PC offers the power of the PS4 at a similar Power perfwith the abilty to function at such low levels (downloading in standby, retaining games in memory for instant access when PS4 is awakened.
5. No PC has the ability to stream all games to a mobille unit as standard.
6. GPU's with direct X 11.2 are very new or just coming on the market meaning that the PS4 GPU is brand new in terms of hardware functionalty and the very latest in cutting edge rivision.
7. No GPU has the amount of ACE's or queues for Compute that the PS4 has.
8. No PC has the drivers to go as low as the PS4 so that devs can expliticty control each part of the hardware.

I will leave you with this quote that I found on Beyond 3d.

"GPUs have evolved to the point where many real-world applications are easily implemented on them and run significantly faster than on multi-core systems. Future computing architectures will be hybrid systems with parallel-core GPUs working in tandem with multi-core CPUs.'
Professor Jack Dongarra
Director of the Innovative Computing Laboratory
The University of Tennessee

I never said the PC cant do it it can do those things. It can but its very ineficent at doing it. And it is limited to how may operations it can to at the same time. Likewise PC devs don't have the resources to target individual cards and their strengths.

So overall the PS4 compares favourably in many aspects and has better bandwidth, more tech advanced (direct x 11.2), and smokes it on GPGPU capabilites. In addition it has nearly twice the bandwidth to the CPU as the 7850 with the abilty for cache bypass or to leave volatile marking on memory so that the CPU can work on the memory without doing a cache flush.

Well we haven't seen what the PS4 is capable of it will take a while but the demonstrations of particles in Second Son, the use of volumetrics on different elements of deepdown and even the sheer amount of voxoles and collision detection on Rasogen are up there with the best examples of GPGPU compute and the PS4 hasnt even launched.

So it's been inefficient to do compute physics on a GPGPU for PC for all these years but not for PS4's GPGPU? The PS4 smokes PC in terms of GPGPU capablitites? The PS4 has DirectX 11.2? DirectX 11.2 will give a relevant boost to physics calculations in a way that will make for the GPU only being a mid-range card? You seem to be fabricating this all out of thin air. Why not post a game that actually outdoes what PC has been doing instead?

So it's been inefficient to do compute physics on a GPGPU for PC for all these years but not for PS4's GPGPU? The PS4 smokes PC in terms of GPGPU capablitites? The PS4 has DirectX 11.2? DirectX 11.2 will give a relevant boost to physics calculations in a way that will make for the GPU only being a mid-range card? You seem to be fabricating this all out of thin air. Why not post a game that actually outdoes what PC has been doing instead?

OK I dont mind a disucssion but quoting me out of contest is not on.

So it's been inefficient to do compute physics on a GPGPU for PC for all these years but not for PS4's GPGPU?

Compared to the PS4 yes for the hardware and software reasons that I have suggested and you haven't produced any evidance that the PC's is more efficient that the PS4 at GPGPU to counter my claims. While I have shown reasons why for what it is the PS4 will be way more efficeient. The only way the PC beats the PS4 is via brute force I stand by my assertion that the PS4 will smoke mid range PC /PC GPU's it has 4 times the aces and over 32 times the compute ques and nearly twice the bandwidth of the PCIe 3.

The PS4 smokes PC in terms of GPGPU capablitites?

In efficency yes PS3 does not have the brute power of the top end machines (neither does it have 600+watt power supply and stand at about six times the volume in size either).

DirectX 11.2 will give a relevant boost to physics calculations in a way that will make for the GPU only being a mid-range card?

Where did I say that Direct X 11.2 would give a boost to phsyics calculations it actually gives advantage for tiling.

Here is a quote I found

Windows 8.1 will bring DirectX 11.2 support, which includes plenty of performance tweaks, new Direct3D features such as Tiled Resources and other goodies. However, there’s still no DirectX 11.2 hardware out there, sort of.

AMD’s GCN-based GPUs are fully compatible with DirectX 11.2 at least in theory. All it takes to make them DX 11.2 enabled is a driver tweak. We suspected HD 7000 series GCN parts were DirectX 11.2 compatible for quite some time and now it’s official.

AMD says the HD 7000 series is fully compatible with DX 11.2 with a new driver, which should appear in the Windows 8.1 launch timeframe, in October.

“Today, AMD is the only GPU manufacturer to offer fully-compatible DirectX 11.1 support, and the only manufacturer to support Tiled Resources Tier-2 within a shipping product stack,” AMD said in a statement.

This means that by the end of the year AMD will have two generations of DirectX 11.2 compatible products, while Nvidia might end up with none. We’ll try to find out more on Nvidia’s DirectX 11.x plans as the Windows 8.1 rollout draws near.

Your claim that the PS4 is "nothing but a mid tier PC" is wrong as no GPU's run direct x 11.2 at the moment but the PS4 will have that ability your trying to play the PS4 down by comapring it to a older generation memory card but I have proven that it is on the cutting edge of this generations GPU's as far as functionalty and hardware and even has extra hardware that no GPU on the market has in the same quanties at this time or anywhere in the near future.

You seem to be fabricating this all out of thin air.

I seem to be the only one pulling in mutlitple sources direct from the manufacturer or direct from the head of design of the PS4 here I havent seen one of my claims debunked by offical sources from you on the other hand.

Why not post a game that actually outdoes what PC has been doing instead?

I have quoted deep down you haven't rebutted the effects shown there yet and shown a superior PC example.

How about the Order 1666

The Order is a third-person shooter, and it’s billed as the first game in a franchise of titles that may also spill out into other forms of media. Set in an alternate post-industrial revolution London, the game’s steampunk, almost Dickensian veneer was researched by a snap-happy studio trip to London, in which Weerasuriya and his crew took over 38,000 photos of the city.

Why? Well, the game’s core hook isn’t steampunk, or the arkane, or even those brilliant twirled moustaches we’ve seen so far. Those photos were actually research for both the game’s aesthetic design and the team’s material creation tools, as well as its bespoke ‘Abel’ physics engine. We were shown photos of zoomed-in cobblestones, of granite and gravel, each taken to make the world of The Order visually impressive, believable and most importantly – destructible.

The game has dynamic destruction, and while we’re not talking about Battlefield 4 levels of military bombast, Ready At Dawn’s surface and environmental destruction is rather impressive. We saw Weerasuriya jump into a stone courtyard and pumped rounds from the protagonist’s Combogun – an assault rifle and shotgun hybrid – into a brass fixture set into a wall. The object crumpled and imploded with force after each round found its mark, deforming it in real-time.

Also check out the many gifs of Infamous Second Son for particle effects and distructablity.

It's day one of Gamescom 2013 and Digital Foundry is attending Sony's indie showcase, playing Housemarque's PS4 debut and talking tech with the developer - and we're hugely impressed with the game. Resogun ticks all the boxes in what we would want from a console exclusive - it's feels great to play, it's technologically groundbreaking, visually arresting and built from the ground up with the capabilities of the host hardware specifically in mind. Remember when Mark Cerny talked about GPU compute becoming more important a few years into the PS4 lifecycle? Resogun - a launch title - is already putting the Radeon graphics hardware through its paces with a range of effects that could only be done on a system built upon a surfeit of GPU power, a console like PlayStation 4.

Enormous explosions, waves of enemies and bullet storms are all par for the course, backed by the screen-filling pyrotechnics you've come to expect from this developer. Housemarque's approach in realising the digital carnage is intriguing: environments are created from hundreds of thousands of cubes, each of which is individually animated by GPU-accelerated physics.

"The entire environment - everything - is built up from these voxels," explains Kruger. "All of the cubes that you see flying around - there's no gimmick, no point sprites, it's not a particle effect, they're actual physical cubes. In gameplay, dynamic cubes with collisions, floating around, you can get up to 200,000. Our engine supports up to 500,000 but in actual gameplay scenarios, it rarely goes over 200K."

The technology behind the cube-based construction of each level is as typically ingenious as you would expect from a Housemarque title.

"It's actually pretty interesting tech because as you can see, the environments are fully destructible and both the background and the gameplay ring are loaded from 3D textures - and then they're polygonised on the fly," Kruger says.

"So basically what happens is that the mesh for the actual background geometry is generated, then when an explosion happens and a part of it is chipped away, that particular segment is reconstructed. That's what's happening on the GPU side with compute shaders - but with nice performance."

Resogun's aesthetic is almost entirely defined by its remarkable physics, and it's a match made in heaven with the compute-heavy skew of the PlayStation 4 hardware. Harry Kruger reels off a list of the various non-render based effects that utilise the PS4 graphics hardware.

"We're using compute shaders for a lot of things like the Overdrive particles you see later, the lightning up there - that's all done on GPU. The actual cubes - the physics and the collisions that you see bouncing, the geometry - that's all done on the GPU-side," he says, before going into more depth on how the 3D texturing works on the 'ring' - the gameplay layer of the environment.

"For the ring, it's the same thing as the background but slightly different tech because here we have one 3D texture that's basically one long rectangular prism. We use these bent cubes, or curved cubes - that's a better way of putting it. Every time an explosion happens these are essentially detached from the world."

Resogun is distinctive because everything about it is designed to service this particular gameplay experience for just this one piece of console technology. In a world where game technology is designed to be scalable across various pieces of hardware with very different performance levels, the result feels fresh and exciting yet, at the same time, evocative of the PS2 era, when the majority of games were built around the specific strengths of Ken Kutaragi's forward-looking hardware. In the present day, it's the PS4's graphics tech and the sheer volume of memory available that are singled out by Housemarque:

"Compute shaders are the big thing and of course the RAM," says Harry Kruger. "We're using over 500 megabytes just for the level geometry. It's all optimised in real-time. We don't have the full 3D texture in memory because as you can see, the level's pretty empty in this case so all the levels are generated into separate sub-meshes."

After a fairly hopeless first effort on our part, Kreuger takes the controls. The screen comes alive with total destruction as he cuts effortlessly through the waves of oncoming enemies, scooping up humans, dropping them off at the rescue point and powering up his weaponry. Heading for terra firma and Overdriving his way through the gun turrets, the screen explodes with hundreds of animated cubes. As our discussion continues, a native 1080p60 is confirmed, with a deferred lighting system in place for theoretically illuminating the scene with hundreds of light sources, but Housemarque is surprisingly restrained in its usage.

"Practically, it would just be too noisy visually," he explains.

On top of the full HD, 60Hz experience, it's clear that Resogun's presentation is extremely clean. A deferred lighting solution would suggest that - in common with most next-gen console games - multi-sampling anti-aliasing (MSAA) is off the table, yet aside from just a tiny touch of pixel flicker around the main ship, Resogun looks really smooth.

Impressive stuff. Resogun has only been in development for 18 months, and the quality of this code - which almost maintains its 1080p60 target - is exceptionally good. For a game that emphasis GPU compute so much, for Housemarque to have come so far so quickly is testament to the skills of its development team. Development of this PS4-specific game must surely have begun on unfinished hardware, and Kruger acknowledges that this is the case. When I suggest that coding for PS4 so specifically on prototype hardware must have been exceptionally challenging, the response is a simple "indeed".

The game you see on this page is described as "work in progress, but relatively indicative of what we're going for" - and we're told that the main push for optimisation has yet to begin. The small dips in the frame-rate will almost certainly be ironed out, and as the demo level concludes with the destruction of the boss and the complete obliteration of the entire level into its individual, GPU-driven component cuboids, we get perhaps the most dramatic example yet of the host hardware's computational power.

So at launch we allready have numerous games that are using some of the compute power of the PS4 GPU this is just first generation and look how fast this indi dev has managed to develope this game 18 months on brand new hardware.

Your completely underestmating Huma the "supercharged GPU" of the PS4 (Mark C's words in quotes not mine) the sony ICE team that done remarkable things with Spurs on Cell that they can port over to the GPU for GPU Compute (yes Sony even has its own compute engines developed since the PS3 started).

I would like to know how I am making things up when you can see the evidance of your own eyes from these first games.

And I would like to see any PC game that stands up to the realtime demo that Quantic Dreams run in the Sorcerer best looking graphics for figures I have ever seen on any platform.

I was alerted to this thread through a link over on the UK official PS4 forum and, since it's a topic I'm particularly interested in, thought I'd pop over and join in

I agree with the main thrust of what @Terrarim is trying to say. Not sure he's putting the argument across succinctly, then again I doubt I could either!

The PS4 seems to be to be a very cleverly designed bit of kit that will prove, long term, to be worth a little more than what we perhaps currently perceive to be the sum of it's parts. I think too many try too hard to compare with PC's and in doing so misunderstand the PS4's hardware design. The one thing it is not is "based on PC architecture". Far from it. Really it just shares a common CPU instruction set and basic GPU technology.

There are two innovations in the PS4 hardware that on their own would be interesting enough, but together? At face value the PS4 has a pretty weak CPU. It's only when you look at the memory architecture and the GPU modifications do you realise why a more powerful CPU isn't needed. The PS4 is designed heavily around GPGPU calculations.

Although PC's have had this technology for a while, there's nothing in the PC world that has been as heavily modified for the purpose of performing these tasks. GPGPU technology really is still in it's infancy, I don't think it's currently used in PC's anywhere near as much as it could be. PC's suffer a lot by being held back by the lowest common denominator.

Gaming on PC's is still largely a single threaded 32bit CPU centric affair. Again held back by the lowest common denominator - Windows XP gamers. Both the XBox One and the PS4 on the other hand are more heavily multithreaded 64bit affairs, with the PS4 being more GPU centric.

Memory wise the hUMA architecture will ultimately free up a lot of wasted clock cycles. Currently GPU data has to be copied to the GPU's memory and back again by the CPU. Just how many clock cycles does it take the CPU to copy 2Gb of data into graphics RAM? Unified memory will get rid of these wasted clock cycles and instead only needs to process on instruction to pass to the GPU 1 memory pointer for the location of the code the GPU needs to process. Massive speed gain - PC's can't do this!

It's when you combine the enhanced GPGPU (8 ACE's with 64 queues) with the efficiency of the hUMA memory bus that you start to unlock the true potential of the PS4's hardware.

Ultimately the PS4 and XBox One's designs are limited by their output media. The TV. Given that the TV set will set a hard limit of 1080p60 gaming for the foreseeable future (4k might be affordable with PS5) does either console actually need any greater graphics power than they have been given?

In truth the answers to this isn't going to be know for another year, maybe more, yet. We need to wait until devs have coded new game engines designed around the consoles hardware - hUMA and GPGPU - before we start seeing games that really do show off what these consoles are capable of and how they do or don't compare to PC's.

Let's face it, the initial batch of games are going to be based upon game engines ported from PC or older games consoles. Based on CPU centric coding and a split memory architecture.

Terarrim, you are just making things up one after another. It's too much to respond to all the misinformation you are putting out. But if you are going to start actually posting evidence, then start with at least proving that PS4 runs DirectX 11.2 and go from there. The PS4 is not some supercharged machine. It's a game console on a tight silicon budget.

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